Root cause of USB boot failure: our xorriso used -e boot/grub/efi.img
to embed the EFI image inside the ISO. This works for CD-ROM and QEMU
but NOT for USB on real UEFI hardware.
Fix: use the Will Haley / Debian live-build approach:
- -append_partition 2 (GPT type EFI) appends efi.img AFTER ISO data
- -e --interval:appended_partition_2:all:: references the appended partition
- --mbr-force-bootable forces MBR active flag
- grub-mkstandalone with embedded bootstrap config (searches for grub.cfg)
- grub.cfg placed in both /boot/grub/ AND /EFI/BOOT/ on ISO
- grub.cfg uses search --label ARCHIPELAGO to find the ISO root
This is the exact approach used by StartOS, TAILS, and every production
custom Debian live ISO that boots from USB.
Also: iso-debug, iso-branding skills + reference docs, dev-start.sh
option 0 for branding dev, improved dev-branding.sh and test-iso-qemu.sh.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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